There are a few key differences between Power BI and Dynamics 365. Dynamics 365 is a cloud-based business application platform that includes CRM and ERP applications, while Power BI is a cloud-based business intelligence platform. Dynamics 365 is focused on business users, while Power BI is focused on data analysis and visualization. Dynamics 365 includes a wide range of applications and features, while Power BI is focused on data analysis and reporting.